Question: What percentage of Earth is arable?: Answer: A little more than 20 percent of the earth’s surface, or about 11.58 million square miles (30 million square kilometers), is capable of sustaining agriculture.

Question: How wide, in miles, is a degree of latitude?: Answer: A degree of arc of latitude is about 69 miles wide.

Question: Which of these cities is sinking into the sea?: Answer: In modern times Venice, Italy, has been sinking into the sea at an alarming rate, and the city’s central region is plagued by flooding.

Question: What is the circumference of Earth at the equator (in kilometers)?: Answer: The equator’s circumference, or length around, is about 25,000 miles (40,000 kilometers).

Question: How long does it take a bottle to bob across the Atlantic Ocean?: Answer: It takes about a year for a bottle to travel from the West Indies to Europe. Other floating objects—including coconut seeds—regularly make the journey, too.

Question: What is the word for land that has fallen down a slope?: Answer: A landslide is a large amount of earth, rock, and other material that moves down a steep slope. An avalanche is similar, but involves snow.

Question: Which of these is not a peninsula?: Answer: A peninsula is a land area that projects into a body of water but is connected to another landmass. An example is the Sinai Peninsula in Egypt, which projects into the Red Sea and links Africa and Asia.

Question: What word describes the bend of a river?: Answer: A meander is a serpentine pattern that a river forms as water erodes the land that contains it.

Question: The world’s longest river is:: Answer: At 4,132 miles (6,650 kilometers) in length, the Nile River is the longest river in the world.

Question: What is the name given to the imaginary line at latitude zero?: Answer: The equator divides the Earth into the Northern and Southern hemispheres and stands at the imaginary zero degree longitude.

Himalayas. Earth Day. Global warming. A satellites view of thick band of haze from agricultural fires and urban pollution near the India Pakistan border along the southwestern face of the Himalaya Mountain range, Oct. 30, 2008. (see notes)

Planet Earth Quiz

What percentage of Earth is suitable for agriculture? What is the Earth’s circumference? Test your inner geographer with this fun quiz.

You have {{ vm.secondsPerQuiz }} seconds to answer each question. The faster you answer, the higher your score. When you're done, try again to beat your best score!

? Stocktrek Images/Thinkstock

:{{vm.state.secondsLeft|fixedLength:2}}

QUESTION {{(vm.state.currentQuestion + 1)}} of {{vm.questions.length}}